After reading the future of rpgs by dwarfsoft, it got me thinking. What if like he said you could enter a word or phase in a box and ask the NPC about it, but if you ask him about a certain word or phase they may ask you more about it. For example you are seeking to find treasure, you ask a NPC "treasure on Island X" they may deny knowledge and ask you more. They could help you or they could search for it themselves

Good idea. You might be able to combine it with a skill to see if the NPCs are telling the truth or not.

Good idea! However, developing each character''s individual knowledge & response database could become quite an undertaking for games like adventure/rpgs. What I mean by this is that the players of the game would expect to have a lot more responses to whatever they type in retrospect to classic games with precomposed conversation. Because of this you''d be forced to implement hundreds (if not thousands) of keywords or phrases that could be caught to generate a response. Many of those keywords would have nothing what-so-ever to do with the game, since the player would be expecting intelligent conversation from the characters. One or two automated responses for things that do not make sense to the character (or do not apply) simply will not do since the player will not always know what to say to progress the storyline. Responses to "incorrect" conversation would come up a lot, so you''d have to have a lot more responses for non-game conversation in order to make the AI believable and fun to interact with. ...but it''s still a cool idea if you can manage these types of obsticles.

There are two suggestions to solve massive speech databases for each character or characters.
1. You could select words or phases in the dialog of the NPCs to ask them about and they would reply. However it may become to much work to just keep asking them about every word in their dialog, so you could only ask them about a certain number of words before they get bored (depending on their personality, tiredness etc.) and also this would prevent cheating.

2. Another idea is that you can give them an item or you can show them a map and they will talk about it. This would reduce the database and provide help for the player if they don''t know about an area or item.

Unfortunately both still need large databases. Here are 2 other ideas that may increase the database but add to game play.
1. NPCs may not want to talk to you. Speaking of which, it might be possible to listen in on their conversations. You could beat information out of them or threaten them.

2. NPCs may also ask you questions, taking the first example, ‘What treasure, where is it?’ and try to get more information about it.

About the skill that tells if their lying, it is a good idea but it might make game too simple. You might have to guess from their dialog. Still under certain circumstances it would definitely add to the realism.